Actuating devices of the initially described type are used in particular to set a water temperature and/or a volumetric flow of water in sanitary facilities.
From DE 19539879 A1 it is known to use three contact-free sensors or a membrane keyboard to request a water flow, set the volumetric flow of the water and select the water temperature. In this case, each sensor is assigned a function. To vary the water temperature and the volumetric flow of the water, the appropriate sensor has to either be actuated a plurality of times or remain actuated.
DE 29505470 U1 proposes by means of a single actuation of a press point within an analogue operator panel with a two-dimensional X-Y arrangement to effect a simultaneous analogue setting of volumetric flow and temperature. Here, if an incorrect press point is inadvertently actuated, this may lead to an undesirable, possibly very large change in the temperature or the volumetric flow. An operator error with serious consequences cannot therefore be ruled out here. In order to allow fine graduation, such a device moreover requires a correspondingly large operator panel.
In other fixtures of the initially described type, control is effected by means of a direct digital numerical input. This poses problems in particular for persons who have difficulty reading numbers, especially preschool children or the visually impaired, with the result that, in this case too, operator errors cannot be ruled out.
The present invention is directed to solving these and other matters.